Is there a Consistent Alien Cannon?

Does the Alien movie series 1-4 and Prometheus create a seamless cannon? Many posters seem to be under the impression that this is so, but having watched documentaries on the making of all 5 movies, I now realize that there are inconsistencies brought about by the changing of directors for each movie. No two movies in that series, and I do not even want to include and AVP movies, were directed by the same director. Each director as we all know, have their own vision but they all at least make an attempt to blend them together with the ones that came before, but not at the expense of their own vision, which is paramount to each of them while in production. It has to be this way. The final result is as work that realistically can only be partially - maybe 80 % constant, the percentage decreasing as the number of movies increased. Between 1 and 2 there is the closest consistency, but even here we have a resulting 2 different life cycles, with Aliens introducing the queen concept. This was due to James Cameron and his great creative genius coupled with his huge ego. He even made little room for Giger because he knew from heresay that Giger would demand to interfere with his artistic vision, by JC's own admission. Look at all the debates that this one change has caused here on this site not to mention elsewhere! Once you get to Alien 3 we are replete with glaring inconsistencies such as where the hell did 2 eggs come from on the Sulaco! What happened to the Ripley-Hicks-Newt family concept, and of course the Charles (Michael?) Bishop Weyland as synthetic debate of just yesterday again! Taking all of this into account it is clear to me that acting as if there is a solid cannon consistent throughout all five movies is unrealistic to say the least. We are talking about 4 separate directors and one that directed the first and fifth movies with 30 years in between. How could we possibly expect it to be any other way. This is the real world of Hollywood blockbuster movie making. The real world concerns of film making, budgetary concerns and timing always take precedence over content unfortunately but this is the way it is, and it is very taxing to all parties concerned especially directors. So imo, I repeat there is no consistent Alien cannon that is inclusive of all 5 movies, and to think otherwise is not realistic.